Biuret derivatives



525-232 SR USS KHIZHIZNCE Imom XR 2 1378 by; 1

UNiTED STATES PATENT OFFICE BIURET DERIVATIVES John KensonSimons, Toledo, (Bhio, and Welcome I. Weaver, Pittsburgh, Pa., assignors, by memo. assignments, to Libbey-Owens-Fotd Glass Company, a corporation of Ohio No Drawing. Application July 8, 1942, Serial No. 450,192

3 Claims. (Cl. 260-553) The invention relates to novel biuret derivamol of biuret increases the speed of thereaction tives and particularly to'novel monomeric reacand also increases the dimculty of separating the tion products of biuret and formaldehyde. crystalline product. The preferred proportion is Large quantities of dimethylol urea are used 3 mols of formaldehyde for every mol of biuret. commercially in the manufacture of organic 6 The reaction can also be carried out with an ex-' soluble reaction products for use in enamels and cess of biuret such as 1 mol of biuret for each other coating compositions. Biuret is one of the mol of formaldehyde. T4 simplest of urea derivatives, but no monomeric Gentle refluxing of the reaction solution on an reaction products of biuret and formaldehyde open flame for 30 minutes as described in Ex- ,2 2, 7 have been known heretofore. Hence, it has not ample 1 produces the same degree of reaction as been possible to use biuret for the preparation of heating for two hours on a water bath, but the organic solutions by a method similar to the exformer procedure is preferred because it protensively used method in which urea is first conduces a reaction product that is more crystalline 4' verted into dimethylol urea and then treated to and easier to purify. Reaction for a longer time 7 produce an organic soluble product. at a slightly lower temperature appears to cause The principal object of the invention is to proconsiderable condensation. "2 vide novel monomeric reaction products of Example 1 ,6

formaldehyde and biuret. More specific objects and advantages are apparent from the description, which discloses and illustrates the invention, and is not intended to impose limitations upon the claims.

Biuret (51.5 grams) is added to .120 grams of b 37 per cent aqueous formaldehyde solution to 2 which has-been added a suflicient amount of 50- per cent aqueous triethanolamine solution to give l The novel rbon m Dun m t the reaction mixture a pH of 7.6. After 30 mini invention hav the geiferifl fori nful a bodyl g he utes of gentle refluxing on an open name,

25 analysis indicates that 1.? mols of formaldehyde have reacted for each mol of biuret. The solution is evaporated in vacuum at room tempera-v m whi i l t from t group consisting ture and the resulting crude crystalline product. f H d cm, is filtered and then washed with acetone. Re-

Dimethylol biuret may be prepared by reactrm crystallization from ethanol or ethyl acetate proing biuret with formaldehyde in aqueous solution duees P cent Yield of dimethylol biuret, a t pH from b t 7 t 9 The preferred pH white substance that melts at 139-l40 C. with: for the reaction is about 7.6. As the reaction decomposition into Br 01881 qui T s proceeds, there is a drop of about .4 to about .6 stance is very soluble in waterand i soluble i of a H, and when t pH has mu to about 7, a hot ethanol or ethyl acetate. but is insoluble in there isno further formation of dimethylol biuret hot 601d aeetonewhen heatedit Sets to a until the pH is raised by addition of a small hard insoluble resinamoimt of an alkali. If the pH is allowed to go Example 2 too low, a viscous solution of a condensation 5 of mammal and 12 drops of 5 normal product results and no dimethylol biuret can hydrochloric acid r added to 11.5 grams of dibe recoveredmethylol biuret. The mixture is stirred for 20 since commemlal aqueous fermeldehyde 50111 minutes to produce a solution, and the acid is then has PH of about base is added to bring neutralized with silver carbonate, and the soluthe PH 01 the Solutien Wlthin the l'equlred rengetion is filtered. Concentration of the filtrate at Any organic or inorganic base, such as triethanol- 5 room temperature under vacuum produces a ami Py e Sodium hydroxide may be crude crystalline product which may be crystalmploye net a o e s preferred ized from Hi-Flash" solvent in large clusters of cause it is a weak base and, therefore, does not 1 12 per cent yield of Lidimetbowmethy} need to be measured out so carefully in adjusting biuret melting at 5 9 Q15 obtained the pH, and because it gives a final product that is less difficult than usual to isolate as a crystalline material. 3 grams of 1,5-dimethoxymethyl biuret, 20

An excess of formaldehyde may be used for the grams of h-butanol and 0.03 gram of maleic acid reaction if desired. A large excess of formaldeare heated to evaporate "f excess of n-butancl;

hyde such as 10 mols of formaldehyde for each The product is a clear, #tyellow viscous liquid which when poured out in a film and baked for 25 to 30 minutes at 105 C. gives a clear hard film that is insoluble in xylene or the monoethyl ether of ethyleneglycol.

Example 4 40 grams of dimethyloi bluret, 400 cc. of methanol and 2 cc. of 5 normal hydrochloric acid are stirred for minutes to produce a solution. The solution is neutralized with silver carbonate and then filtered. After the addition of 400 cc. of nbutanol and .5 gram of maleic acid to the filtrate, the solution is concentrated by vacuum distillation to produce 100 grams of a clear, slightly yellow coating composition containing 51 per cent solids. When poured out in a film and baked at 115 C. for to minutes, this composition produces a clear hard film.

Example 5 An alcohol solution containing grams of dimethylol biuret is brought to a pH below 6 by addition of alcoholic phthalic acid, and the resulting solution is used to impregnate 50 grams of alphacellulose. After the mass has been dried in an oven at C., 1 per cent by weight of zinc stearate is added and the mixture is pulverizedin a ball mill. The resulting composition, can be molded at a temperature of 50-160 C. under a pressure of 1 to 4 tons per square inch.

Variou embodiments of the invention may be devised to meet various requirements.

Having described the invention, we claim:

1. A novel carbon compound having the general formula R-O-CHz-NH-CO-NH-CO-NH-CHz-O-R in which R is selected from the group consisting of H and CH3.

2. As a. novel carbon compound, 1,5-dimethylol biuret.

3. As a novel carbon compound, 1,5-dimethoxymethyl biuret.

JOHN KENSON smoNs. wmco mr. 

